Sketchup Free: Einzelteile vom Entwurf als STL?

Wie kann man in SketchUp Free (Browserversion) “einzelne” Teile eines Entwurfes als STL erstellen? Nicht “alle” Teile insgesamt in eine einzige STL?
Man stelle sich ein Haus vor, bestehend aus Erdgeschoss, Dach und Anbau und möchte nur das Dach oder nur den Anbau als STL erstellen. Wie geht das?

Translated by Google:

Delete everything you don’t want to include in the .stl file, download the .stl file, and then undo the deletion if you want. Or a safer method would be to first use Save as to create a new file, then delete what you don’t want and make the export.

Your forum profile says you have SketchUp 2020 Pro. Why aren’t you using it to create your model? You could then export only the selected object(s) to .stl.

Thanks,
I myself work with SU Pro 2020 very happy. But the young Boy of my Daughter is working with SU Free. I try helping him.
(Sorry, I made a second Thread according to the same Problem).

But: Why this uncomfortable work to solve the Problem? I mean it is not a big Deal for Developers or Programmers, give the Free Version an Update making it easy - or?

It’s good of you to help him. Show him how to do what I described and he should be good.